Binding of translation elongation factors to individual copies of the archaeal ribosomal stalk protein aP1 assembled onto aP0.
Binding of translation elongation factors to individual copies of the archaeal ribosomal stalk protein aP1 assembled onto aP0.
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翻译延伸因子与组装到 aP0 上的古细菌核糖体茎蛋白 aP1 的各个副本的结合。
DOI：
10.1016/j.bbrc.2016.12.175
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Uchiumi T.
中科院分区：
文献类型：
--
作者：
Honda;T.;Imai;H.;Suzuki;T.;Miyoshi;T;Ito K;Uchiumi T.
所有生物体中的核糖体都含有称为柄的寡聚和柔性蛋白质，其负责将翻译的GTd 3因子募集到核糖体。线粒体核糖体有三个茎同源二聚体（aP 1）2，它们与锚蛋白aP 0构成七聚体复合物。我们研究了因子结合能力的aP 1蛋白组装到aP 0，凝胶阻滞试验。分离的aP 0（aP 1）2（aP 1）2（aP 1）2复合物，以及与大肠杆菌50 S核心结合的形式，作为杂合50 S颗粒，与延伸因子aEF 2强烈相互作用，但与aEF 1A弱相互作用。这些相互作用被破坏的点突变，F107 S，在C-末端的aP 1。为了检测aP 0相关的aP 1的每个拷贝与延伸因子结合的能力，我们构建了aP 0·aP 1变体三聚体，其由aP 0突变体和单个（aP 1）2二聚体组成。生化和定量分析表明，得到的三个三聚体，aP 0（aP 1）2 I，aP 0（aP 1）2 II和aP 0（aP 1）2 III，分别结合两个分子的aEF 2，表明aP 0·aP 1三聚体中的aP 1 C-末端区域的每个拷贝可以紧密结合aEF 2。有趣的是，aEF 1A与三种aP 0·aP 1三聚体的不稳定结合在aEF 2存在下显著稳定。aEF 1A与茎复合物结合的稳定性可能受到与复合物结合的aEF 2的存在的影响，其机制未知。
Ribosomes in all organisms contain oligomeric and flexible proteins called stalks, which are responsible for the recruitment of translational GTPase factors to the ribosome. Archaeal ribosomes have three stalk homodimers (aP1)2that constitute a heptameric complex with the anchor protein aP0. We investigated the factor binding ability of aP1 proteins assembled onto aP0, by gel-retardation assays. The isolated aP0(aP1)2(aP1)2(aP1)2complex, as well as the form bound to theEscherichia coli50S core, as a hybrid 50S particle, interacted strongly with elongation factor aEF2, but weakly with aEF1A. These interactions were disrupted by a point mutation, F107S, at the C-terminus of aP1. To examine the ability of each copy of aP0-associated aP1 to bind to elongation factors, we constructed aP0·aP1 variant trimers, composed of an aP0 mutant and a single (aP1)2dimer. Biochemical and quantitative analyses revealed that the resultant three trimers, aP0(aP1)2I, aP0(aP1)2II, and aP0(aP1)2III, individually bound two molecules of aEF2, suggesting that each copy of the aP1 C-terminal region in the aP0·aP1 trimers can bind tightly to aEF2. Interestingly, the unstable binding of aEF1A to each of the three aP0·aP1 trimers was remarkably stabilized in the presence of aEF2. The stability of the aEF1A binding to the stalk complex may be affected by the presence of aEF2 bound to the complex, by an unknown mechanism.